Function decodeRing

test/data/map/decode.js:70–92

(coordinate, encodeOffsets, encodeScale)

}

function decodeRing(coordinate, encodeOffsets, encodeScale) {
    var result = [];
    var prevX = encodeOffsets[0];
    var prevY = encodeOffsets[1];

    for (var i = 0; i < coordinate.length; i += 2) {
        var x = coordinate.charCodeAt(i) - 64;
        var y = coordinate.charCodeAt(i + 1) - 64;
        // ZigZag decoding
        x = (x >> 1) ^ (-(x & 1));
        y = (y >> 1) ^ (-(y & 1));
        // Delta decoding
        x += prevX;
        y += prevY;

        prevX = x;
        prevY = y;
        // Dequantize
        result.push([x / encodeScale, y / encodeScale]);
    }

    return result;
}

// Export for testing.
if (typeof module !== 'undefined') {